Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 2080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 466.79
Broken: version: 2.93.3, branch: master, commit date: 2021-08-17 18:30, hash: rB8b80d19f3641
If the opacity of the annotation is using keyframing, the keyframe is created, but the opacity does not change when frame changes.
Not sure if we must avoid the animation for this value as we already do with Thickness. Really, annotations are not designed to do these things.